Stretch wrap film is used to wrap bundles of articles so that they can be handled as one unit. Stretch wrap film is typically made from linear low density polyethylene (LLDPE), low density polyethylene (LDPE), linear ultra low density polyethylene (LULDPE), ethylene vinyl acetate (EVA), or a mixture thereof. Blown film is preferable to cast film where strength is a factor. LLDPE and LULDPE have sufficient tensile strength and puncture resistance to be suitable for use in blown film applications. It is typical for stretch wrap film to be elongated 200 percent, or more, in commercial applications. Since LLDPE and LULDPE films often do not have adequate peel cling strength after being stretched 200 percent a cling additive may be added to the film.
In addition to the properties of adequately high tensile strength and adequately high peel cling strength, stretch wrap film should preferably have relatively low unwinding noise. This is important in light of the OSHA noise workplace restrictions. The high speed unwinding noise of LLDPE and LULDPE based stretch films is often above 85 decibels. U.S. Pat. No. 5,273,809 discloses that the addition of cling additives adversely affects the unwinding noise level of the resulting films. Furthermore, it is known that blown film containing a cling additive will generally have a higher noise level than cast stretch film.
In light of the above, it would be desirable to have a high speed, lower noise, stretch wrapping process for stretch cling film. It would be further desirable if such process provided lower noise level when using stretch film containing an amount of cling additive sufficient to provide high peel cling strength to the film.